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tls: zero the crypto information from tls_context before freeing

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This contains key material in crypto_send_aes_gcm_128 and
crypto_recv_aes_gcm_128.

Introduce union tls_crypto_context, and replace the two identical
unions directly embedded in struct tls_context with it. We can then
use this union to clean up the memory in the new tls_ctx_free()
function.

Fixes: 3c4d755915 ("tls: kernel TLS support")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sabrina Dubroca 2018-09-12 17:44:42 +02:00 committed by David S. Miller
parent 7cba09c6d5
commit 86029d10af
5 changed files with 32 additions and 23 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

19
include/net/tls.h
View file

@ -171,15 +171,14 @@ struct cipher_context {
char *rec_seq;
};
union tls_crypto_context {
struct tls_crypto_info info;
struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
};
struct tls_context {
union {
struct tls_crypto_info crypto_send;
struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
};
union {
struct tls_crypto_info crypto_recv;
struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
};
union tls_crypto_context crypto_send;
union tls_crypto_context crypto_recv;
struct list_head list;
struct net_device *netdev;
@ -367,8 +366,8 @@ static inline void tls_fill_prepend(struct tls_context *ctx,
* size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
*/
buf[0] = record_type;
buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.info.version);
buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.info.version);
/* we can use IV for nonce explicit according to spec */
buf[3] = pkt_len >> 8;
buf[4] = pkt_len & 0xFF;

6
net/tls/tls_device.c
View file

@ -686,7 +686,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
goto free_marker_record;
}
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
switch (crypto_info->cipher_type) {
case TLS_CIPHER_AES_GCM_128:
nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
@ -780,7 +780,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
ctx->priv_ctx_tx = offload_ctx;
rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
&ctx->crypto_send,
&ctx->crypto_send.info,
tcp_sk(sk)->write_seq);
if (rc)
goto release_netdev;
@ -862,7 +862,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
goto release_ctx;
rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
&ctx->crypto_recv,
&ctx->crypto_recv.info,
tcp_sk(sk)->copied_seq);
if (rc) {
pr_err_ratelimited("%s: The netdev has refused to offload this socket\n",

2
net/tls/tls_device_fallback.c
View file

@ -320,7 +320,7 @@ static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
goto free_req;
iv = buf;
memcpy(iv, tls_ctx->crypto_send_aes_gcm_128.salt,
memcpy(iv, tls_ctx->crypto_send.aes_gcm_128.salt,
TLS_CIPHER_AES_GCM_128_SALT_SIZE);
aad = buf + TLS_CIPHER_AES_GCM_128_SALT_SIZE +
TLS_CIPHER_AES_GCM_128_IV_SIZE;

20
net/tls/tls_main.c
View file

@ -241,6 +241,16 @@ static void tls_write_space(struct sock *sk)
ctx->sk_write_space(sk);
}
static void tls_ctx_free(struct tls_context *ctx)
{
if (!ctx)
return;
memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
kfree(ctx);
}
static void tls_sk_proto_close(struct sock *sk, long timeout)
{
struct tls_context *ctx = tls_get_ctx(sk);
@ -294,7 +304,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
#else
{
#endif
kfree(ctx);
tls_ctx_free(ctx);
ctx = NULL;
}
@ -305,7 +315,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
* for sk->sk_prot->unhash [tls_hw_unhash]
*/
if (free_ctx)
kfree(ctx);
tls_ctx_free(ctx);
}
static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
@ -330,7 +340,7 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
}
/* get user crypto info */
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
rc = -EBUSY;
@ -417,9 +427,9 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
}
if (tx)
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
else
crypto_info = &ctx->crypto_recv;
crypto_info = &ctx->crypto_recv.info;
/* Currently we don't support set crypto info more than one time */
if (TLS_CRYPTO_INFO_READY(crypto_info)) {

8
net/tls/tls_sw.c
View file

@ -1055,8 +1055,8 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
goto read_failure;
}
if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.version) ||
header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.version)) {
if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.info.version) ||
header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.info.version)) {
ret = -EINVAL;
goto read_failure;
}
@ -1180,12 +1180,12 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
if (tx) {
crypto_init_wait(&sw_ctx_tx->async_wait);
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
cctx = &ctx->tx;
aead = &sw_ctx_tx->aead_send;
} else {
crypto_init_wait(&sw_ctx_rx->async_wait);
crypto_info = &ctx->crypto_recv;
crypto_info = &ctx->crypto_recv.info;
cctx = &ctx->rx;
aead = &sw_ctx_rx->aead_recv;
}